Clip-on or snap-on fastening for fixing a thin wall to a wall support

ABSTRACT

The description relates to a snap fastening for fixing a thin wall, such as a housing wall, door leaf, or shutter, which is provided with an opening, to a wall support such as a housing frame, door frame, or wall opening edge, which is likewise provided with an opening, with a base part that can be arranged at the wall support in its opening, with a head part which extends away from this base part and which has a diameter that initially increases and then decreases again in its longitudinal section from the end of the head part in direction of the base part, which head part is a male plug-in part which, by overcoming a spring force acting radially outward in direction of the diameter, can be received by an undercut female plug-in part that is formed or carried by the opening of the thin wall.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of International Application No.PCT/EP2005/002084, filed Feb. 28, 2005 and German Application No. 202004 003 238.4, filed Feb. 27, 2004, German Application No. 20 2004 005083.8, filed Mar. 29, 2004 and German Application No. 20 2004 016 009.9,filed Oct. 15, 2004, the complete disclosures of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

The invention is directed to a snap fastening for fixing a thin wall,such as a housing wall, door leaf, shutter, or the like, which isprovided with an opening, to a wall support such as a housing frame,door frame, wall opening edge, or the like, with a base part that can bearranged at the wall support in the opening, with a head part whichextends away from this base part and which has a diameter that firstincreases and then decreases again in its longitudinal section from theend of the head in direction of the base part, and which head part is amale plug-in part which, by overcoming a spring force acting radiallyoutward in direction of the diameter, can be received by an undercutfemale plug-in part that is formed or carried by the opening of the thinwall.

BRIEF DESCRIPTION OF THE PRIOR ART

A snap fastening of the type mentioned above is already known from apamphlet published by Böllhoff GmbH, Archimedesstr. 1-4, 33649Bielefeld. A pin which can be fastened to the wall support by means of abase part having a thread has a spherical or balloon-shaped headconstituting the male plug-in part, while a cap which is provided with acollar serves as the female plug-in part and can be inserted into anopening in the thin wall and makes it possible to receive the head in aflexible manner because of the construction material which comprises aflexible plastic.

It is disadvantageous that the plastic material can lose its integrityand springiness over the course of time and with frequent stress andthat the strength of the holder is not ensured. Further, theconstruction is very complicated and expensive.

OBJECT AND SUMMARY OF THE INVENTION

It is the primary object of the invention to provide a snap fastening ofthe type mentioned above which overcomes these disadvantages and ensuresexcellent springiness over an unlimited period of time and in which thedesign, due to its simplicity, enables inexpensive production and asimple assembly makes it possible to produce, e.g., sheet metal cabinetsand all types of casings, coverings and end closures less expensively.

This object is met in that the head part in a snap fastening of the typementioned in the beginning is a guide or channel for one or two or morepush elements which are pushed by means of at least one spring into aposition in which they project out over the end of the guide or channel,and the ends of the push elements projecting from the guide channel aretriangular or ball-shaped in a projection plane extending perpendicularto the thin wall.

By means of this step, a steel spring with spring characteristics whichdo not change over time can be used, in contrast to the prior art inwhich the spring force must be provided by plastic material whichchanges over time.

Another advantage consists in that the spring force can be made as highas possible simply by using spring devices having correspondingly highspring constants, whereas the springiness in plastics is limited by thematerial characteristics of the plastics.

In the prior art, the female plug-in part must be arranged in a roundopening in the thin wall; in the embodiment form, according to theinvention, the female plug-in part is preferably formed by a rectangularopening in the thin wall, preferably in a bevel area at the edge of thethin wall, so that it is possible to provide a narrower, and thereforesmaller, opening without impairing strength.

In a particularly advantageous embodiment form according to theinvention, the push elements comprise two plates which lie next to oneanother (or one behind the other) so as to be displaceable, each of thetwo plates having an opening which is elongated in the movementdirection and which forms, individually or jointly, a receiving spacefor a spiral

pressure spring, wherein the openings in the second end are arranged soas to be moved away from the ball-shaped or triangular free ends in sucha way that the shared spring forces the two plates apart in theirmovement direction.

According to another construction of the invention, the edges of theopenings have projections or recesses for fixing the spiral pressurespring and the plates. Accordingly, the spiral spring can be fitted inthe plates or plate beforehand so as to facilitate subsequent assemblyin a male plug-in part.

According to another construction of the invention, the pressure springand the opening edges are shaped in such a way that the pressure springholds the two plates against one another so as to form a handling unitthat can be preassembled.

This also contributes to simplifying handling before and duringassembly.

According to a further development of the invention, the plates have anotch at their outer longitudinal edge for limiting their longitudinalmovement by means of a projection or pin which engages in the notch. Ina particularly advantageous manner, according to the invention, the twoplates are guided so as to be displaceable longitudinally in a U-shapedhousing whose leg ends are fastened to a base plate formed by the basepart or are formed integral with the base plate.

The U-shaped housing can have an opening in the web area for receiving apin which serves to limit the longitudinal movement of the plate orplates as was already described.

The base part can be formed by a screw bolt by which the base part canbe fastened to a wall support such as a housing frame, wall openingedge, and the like, by screwing a nut onto the bolt. This corresponds tothe type of fastening of the pin in the prior art.

Alternatively, the base part can also be formed by a fastening plateprovided with fastening holes in order to make it possible to fasten thebase part by means of corresponding screws that can be inserted throughthe fastening holes.

The base part can also be formed by a plate which overlaps thelongitudinal edges of the opening in the thin wall.

The base part can also be a side of a pressed metal profile, such as analuminum profile, or of a rolled sheet-metal profile, such as asheet-steel profile, or of an injection-molded plastic profile.

In a particularly advantageous manner, the base part is formed similarto the head part in a mirror-inverted arrangement. In an embodiment formof this kind, it is advantageous when both parts have a common baseplate lying between them.

However, the base plate of the head part can also be formed or carriedby the web of the base part.

In this case, it is advantageous when the base part has a greaterlongitudinal extension than the head part and, with its web, formssupport shoulders for the thin wall. This provides a stop perpendicularto the plane of the thin wall which then need not be formed by otherstructural component parts of the wall support or of the housing.

The free ends of the displaceable plates of the base part can have anasymmetric roof shape such that the base part can be inserted into asuitable opening in a thin wall or wall support by inserting thelongitudinally displaceable plates while guiding the part of the roofwith the flatter inclination, but a backward movement while guiding thesteeper part of the roof is impossible because the plates areself-locking in their guide.

An arrangement of this type cannot be disengaged again without specialtools, which is advantageous in many cases.

When self-locking snap fastenings are used, it is advantageous when atool such as a wrench or key which is capable of pulling back the pushelements against the spring force by turning it can be inserted from thefront and/or back into the housing comprising the self-locking snapfastening.

This makes it possible to disassemble a fastening of this kind ifrequired.

According to another embodiment form of the invention, the housing canbe provided with fastening cams which can be clipped into athrough-opening in a thin wall.

An actuating shaft or actuating wheel or a key by which the pushelements of the housing can be pulled back can project from the housing.

The actuation of a snap fastening in which a plurality of actuatingwheels are provided is facilitated when the actuating wheel is designedin such a way that it can lock in the open position.

A grip device can also project from the housing. This is moreadvantageous, for example, when the housing is a drawer or a push-inrack.

The housing can comprise a snap fastening which is not self-locking aswell as a snap fastening which is self-locking. The two types of snapfastening are arranged at the same height or so as to be offset relativeto one another with respect to the distance from the plane of the thinwall.

The base part can have elongated holes as fastening holes, which isadvantageous when the arrangement serves as a bracket which is to bescrewed in so as to be displaceable.

The invention is also directed to a drawer or rack with a thin-walledfront area, wherein the front plate is the thin wall and the drawerreceptacle is the wall support.

The invention is also directed to a cabinet with a thin wall or doorleaf in which the snap fastening is constructed according to one of theembodiments mentioned above.

The thin wall can have one or more handles or recessed grips tofacilitate handling of the thin wall. In this case, it is advantageouswhen the grip recesses are arranged in openings in which a snapfastening engages similar to that of the base part shown in thepreceding embodiment forms.

A double-bevel makes it possible to arrange the fastening so that it isnot visible. Alternatively, it is also possible to provide the thin wallwith webs which have openings for receiving the symmetricallyroof-shaped ends of the snap fastening according to one of the precedingembodiment forms.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained more fully in the following withreference to embodiment examples shown in the drawings.

FIG. 1A shows a switch cabinet door which is articulated at a switchcabinet frame and is held in a closed position by a snap fasteningconstructed according to the invention;

FIG. 1B shows a sectional top view of the opening provided in the doorleaf and in the door frame for the snap fastening constructed accordingto the invention;

FIG. 2 shows a side view of the snap fastening used in FIG. 1A whichserves as a door closure and which can be fastened to the door frame bymeans of a base part in the form of a similarly constructed snapfastening;

FIG. 3A is a perspective view of a snap fastening with a base part thatis formed by a fastening plate provided with fastening bore holes;

FIG. 3B is a side view of a snap fastening with a base part that isformed by a fastening plate provided with fastening bore holes;

FIG. 4 shows an embodiment form in which the base part is formed by ascrew bolt;

FIG. 5A is a perspective view of a twofold U-shaped housing for twoplates which are arranged so as to be displaceable relative to oneanother;

FIG. 5B is a front view of a twofold U-shaped housing for two plateswhich are arranged so as to be displaceable relative to one another;

FIG. 5C shows a view in axial section along section plane B-B of FIG.5B; and

FIG. 5D shows a top view of the housing according to FIG. 5A;

FIG. 6 shows a plate provided with an opening and side edge cutout forrealizing the snap fastening at the door frame;

FIG. 7A is a perspective view of a mounting plate which has a symmetrictriangular tip and is provided with an opening and a side edge notch;

FIG. 7B is a side view of a mounting plate which has a symmetrictriangular tip and is provided with an opening and side edge notch;

FIG. 7C is a top view of a mounting plate which has a symmetrictriangular tip and is provided with an opening and side edge notch;

FIG. 8 is a top view of a mounting plate which has a symmetrictriangular tip and is provided with an opening and side edge notch,wherein one triangle side of the tip is concave;

FIG. 9 is a top view of a mounting plate, wherein the tip is ball-shapedand has a convex triangle side;

FIG. 10A shows a sectional view similar to that in FIG. 1A through acabinet wall provided with a snap fastening constructed according to theinvention;

FIG. 10B shows a sectional view along section line A-A of FIG. 10A;

FIG. 10C shows a top view of the embodiment form according to FIG. 10A;

FIG. 10D shows a perspective view of the arrangement according to FIG.10A;

FIG. 11A shows the side frame with a side wall of a cabinet in whichsnap fastenings according to the invention and recessed handlearrangements are provided;

FIG. 11B shows an enlarged sectional view along line E-E of FIG. 11A;

FIG. 11C shows an enlarged sectional view along section line D-D of FIG.11A;

FIG. 11D shows a perspective view of the frame according to FIG. 11Awith a snap fastening constructed according to the invention accordingto FIGS. 11B and 11C;

FIG. 12 shows a cross section through the frame of a cabinet providedwith a door leaf and its snap fastening;

FIGS. 13A and 13B show a top view and a sectional view along line F-F ofFIG. 13A of the cabinet according to FIG. 12 to illustrate a holderwhich is welded to the rear surface of the door leaf and which hasopenings for receiving the ends of the push plates of the snapfastening;

FIGS. 14A to 14D show embodiment forms of the push plates withconstructions for forming a handleable unit comprising plates andsprings;

FIG. 15A is a sectional view of a snap element in which the base part isformed by a plate 218;

FIG. 15B is a side view of a snap element in which the base part isformed by a plate 218;

FIG. 16A is a sectional view of a snap element in which the base part isformed by a plate 218;

FIG. 16B is a side view of a snap element in which the base part isformed by a plate 218;

FIG. 16C shows the housing according to FIG. 16A or with a tool forpressing in an inwardly facing projection for fixing the plates;

FIG. 17A is a sectional view through a type of snap fastening similar tothat in FIG. 2, but using sheet metal;

FIG. 17B shows an arrangement similar to that in FIG. 1A, but againproduced using sheet metal;

FIG. 17C shows the associated housing of the clippable connection part;

FIG. 17D is a sectional view through the plates which can be introducedin the housing according to FIG. 17A;

FIG. 18 shows a housing shape similar to that in FIG. 17C, but with aprojecting guide for plates;

FIG. 19A is a side view of a housing produced by injection molding;

FIG. 19B is a view from the side of a housing produced by injectionmolding;

FIG. 19C is a top view of associated plates;

FIG. 19D is a side view of associated plates;

FIG. 20 shows a housing similar to that in FIG. 18, but which isproduced by injection molding;

FIGS. 21A, 21B show an embodiment form according to FIGS. 15A, 15B witha particularly stable holder, screwed;

FIG. 21C is a rear view of the embodiment form according to FIG. 21Ashowing that two pairs of plates are provided;

FIG. 22A is a view similar to that in FIG. 21A, but in which the platesare arranged one behind the other rather than next to one another;

FIG. 22B is aside view of the embodiment form according to FIG. 22A;

FIG. 22C is a top view of the embodiment form according to FIG. 22A;

FIGS. 23A, 23B, 23C and 23D show the associated shortened plate withspring;

FIGS. 24A, 24B and 24C show three views of an alternative, especiallystable snap element;

FIGS. 25A, 25B and 25C show different views of a snap element which canbe locked by means of a stopper or plug and which can be unlocked bymeans of a key;

FIGS. 26A to 26B and 27A to 27C show different views of the associatedpush plates;

FIGS. 28A, 28B, 28C and 28D show an embodiment form with a securedspring;

FIGS. 29A to 29C show the associated plate and the accompanying spring;

FIGS. 30A, 30B show another embodiment form;

FIG. 31 shows the associated housing;

FIGS. 32A and 32B show the associated plate;

FIGS. 33A and 33B show another embodiment form;

FIGS. 34A to 34D show an embodiment form similar to that in FIG. 20which can be unlocked by a key;

FIG. 35 shows the associated opening in the thin wall;

FIG. 36 shows an application which can be opened from the outside;

FIG. 37 shows a corresponding application which can be opened from theback;

FIGS. 38A and 38B show openings for the thin wall and wall support usinga housing according to FIGS. 41A and 41B;

FIGS. 39A and 39B show the corresponding openings for an embodiment formaccording to FIGS. 40A to 40C;

FIGS. 40A to 40D show a housing that can be locked by means of clipprojections in the wall support which are formed by the housing wall;

FIGS. 41A and 41B show another corresponding shape;

FIG. 42 shows an axial section through the housing according to FIGS.40A to 40D;

FIGS. 43A to 43B show another embodiment form which employs a grip;

FIG. 44 shows a sectional view of an application with an embodiment formwhich can be unlocked by means of a wheel;

FIGS. 45A to 45C show an embodiment form with a grip in which theself-locking fastening and the fastening that is not self-locking arearranged in an individual housing;

FIG. 46 shows an embodiment form in a view similar to that in FIG. 45 inwhich the self-locking fastening and the fastening that is notself-locking are arranged on different planes in the same housing;

FIG. 47 shows the associated opening shape for the embodiment formaccording to FIGS. 45A to 45C;

FIG. 48A shows a front view of suitable self-locking plates for theembodiment form according to FIGS. 45A and 45B; and

FIG. 48B shows a side view of suitable self-locking plates for theembodiment form according to FIGS. 45A and 45B;

FIG. 48C shows the corresponding view for a plate that is notself-locking;

FIGS. 49A, 49B and 49C show the view of another alternative for aself-locking plate;

FIGS. 50A, 50B and 50C show a snap fastening constructed according tothe invention which can be used as a bracket;

FIGS. 51A and 51B show a view in longitudinal section and in crosssection through an embodiment form constructed as a connector of twothin walls;

FIGS. 52A and 52B show a side view and a top view of the connectoraccording to FIG. 51A;

FIG. 53 shows a view similar to that in FIG. 51B, but in which the wallsare not yet connected;

FIG. 54 is a side view of a snap fastening with holding elements whichare swivelable around an axis extending parallel to the plane of thethin wall;

FIGS. 55A, 55B and 55C show a side view of a snap fastening with holdingelements which are swivelable around an axis extending perpendicular tothe thin wall;

FIG. 56 shows an exploded view of a snap fastening similar to that shownin FIGS. 40A to 40C, but in which an insertable spring is providedinstead of a fastening cam;

FIGS. 57A-F show different views of the snap fastening according to FIG.56 in a closed position;

FIGS. 58A-E show different views of the snap fastening according to FIG.56 in the open position;

FIG. 59 shows a perspective view of the snap fastening according to FIG.56 before being mounted in a wall support and before the thin wall ismounted at the wall support by means of the snap fastening;

FIG. 60A shows a perspective view of the snap fastening according toFIG. 56 after it is mounted in a wall support and before the thin wallis mounted at the wall support by means of the snap fastening;

FIGS. 60B-D show other views of the situation depicted in FIG. 60A;

FIG. 61A is a perspective view of the snap fastening according to FIG.56 after it is mounted in a wall support and after the thin wall ismounted at the wall support by means of the snap fastening; and

FIGS. 61B-D show other views of the situation depicted in FIG. 61A.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1A is a cross-sectional view showing a snap fastening 10 for fixinga thin wall 14, such as a housing wall, in this case a door leaf 14,shutter, or the like, which is provided with an opening 12, to a wallsupport 16 such as a housing frame, door frame, wall opening edge, orthe like, which is likewise provided with an opening 12, having a basepart 18 that can be arranged at the wall support 16 in the opening 12,with a head part 20 which extends away from this base part 18 and whichhas in its longitudinal section, shown as a side view in FIG. 2, adiameter that first increases and then decreases again from the end ofthe head part 20 in direction of the base part 18, which head part 20 isa male plug-in part which, by overcoming a spring force (see spring 28in FIG. 3B) acting radially in direction of the longitudinal section,can be received by an undercut plug-in part that is formed or carried bythe opening 13 in the thin wall 14. The head part 20 of the snapfastening 10 has guides or channels 33, 34 for one or two push elements23 which is/are pushed by at least one spring 28 into a position (seeFIG. 3B) in which they project over the end of the guide channel. Theend projecting from the guide channel 33 or 34 has a triangular shape(see FIG. 2, top, and FIG. 7B), that is, it comprises inclined surfacesor triangle sides 25, 27 as can be seen from FIG. 7B. Two push elements23 which are identically constructed in this way are arranged next toone another inside the channel 33, 34 so as to run in oppositedirections and are displaceable opposite one another and with respect tothe four walls of the channel. This back-and-forth movement of the pushelements 23 is limited by a shoulder 42 which can be part of a stopperor plug 66 and which is arranged through a matching opening 32 (see FIG.5D) in the narrow wall of the head part 20. This shoulder projects intoa recess 79 of the push element 23 and strikes its end faces 38, 39.Accordingly, while the plug 66 is located in the position shown in FIG.3B, the two push elements 23, 123 running in opposite directions cannotfall out of the housing guide; on the other hand, they are pressed bythe spring 28 into a position shown in FIG. 3B in which they projectover the guide channels by the tips of their triangles. The inclinedsurfaces 25, 27 accordingly form the above-mentioned diametricalextension of the head part which initially increases and then decreasesagain. Accordingly, this snap element 10 can be pushed into the opening12 formed by the door leaf 14. The inclined surface 27 slides along thenarrow edge of this opening and, in doing so, pushes the push element 23back into the guide channel against the force of the spring 28 until thetip of the triangle is reached, whereupon the push element 23 movesoutward again and the edge of the opening slides down along the inclinedsurface 25 and causes the snap element to move out of the opening again.When its inclination is the same as that of the inclined surface 27, theinclined surface 25 permits an outward movement which, however, can alsobe modified in that this inclined surface 25 has a concave shape asindicated by 25′ or a convex shape as indicated by 27′, so that theexpenditure of force needed for unlocking the snap element again ischanged.

As can be seen in FIG. 1A, the opening 12 for the snap fastening islocated at a bevel of the door leaf 14, so that the fastening is notvisible when the door is closed. Instead of the opening of the housing16 being closed by a door having a hinge 11 and a door handle 15, theopening of the housing 16 can also be closed by means of a wall part inwhich, instead of the hinge 11, a snap fastening similar to that shownon the left-hand side at 10 could be arranged over openings 112, 113.This wall 114 can have a second handle 115 to facilitate operation, buta handle can also be omitted.

In general, the bevel of the frame 16 shown on the left-hand side inFIG. 1A can be a wall opening which is to be closed by a correspondingclosure part.

The fastening of the snap element 10 at the door frame 16 or the likecan be carried out in a conventional manner by means of a screw bolt(see the bolt arrangement 219 arranged at the base plate 218 in FIG. 4)or, according to FIGS. 3A, 3B, by means of screws, not shown, which arearranged through bore holes 119 in the base plate 118. A more favorabledesign which is adapted to the upper portion of the snap fastening andwhich is likewise shown in FIG. 1 consists in that the base part isconstructed substantially identical to the head part 21.

The substantial difference consists in that the inclined surfaces 26, 24have different inclinations (see FIG. 6). The inclined surface 26facilitates the insertion of the base part into a corresponding opening12, 112 in a frame or the like by providing a relatively slightinclination which does not allow a self-locking effect. In contrast, theinclination 24 that must be overcome in order to pull the structuralcomponent part out of the opening again is so steep that there is aself-locking effect and the structural component part cannot be removedfrom the opening without a special tool.

A particularly advantageous application of the spring force isillustrated in FIGS. 14A to 14D. The two push elements comprise twoplates 122 which lie next to one another so as to be displaceable (seeFIG. 14B), each having an opening 146 that is elongated in the movementdirection. These two openings which lie next to one another togetherform a receiving space for a spiral pressure spring 128. The openings146 are arranged so as to be displaced away from the ball-shaped ortriangular free ends in such a way that the spring forces the two platesapart in their movement direction, that is, to the right and to the leftin FIG. 14B.

The other edges of the opening 146 can have projections 186 in order tofix the spring inside this receiving space or so that the two adjacentdisplaceable plates 122 can be held together at the same time as ahandleable unit as is illustrated in FIGS. 14C and 14D (different platethicknesses).

When this mounting unit is not required or if the arrangement supportsitself already, the projection 186 can also be omitted. In any case,after mounting in the channels, the springs and the plates are heldrelative to one another automatically, that is, by the walls of thechannels.

Therefore, the construction of the snap fastening according to FIG. 2 isparticularly advantageous insofar as the snap fastening can be fastenedin the frame 16 by a clipping process and a thin wall, such as door 14,can then be slid over the snap fastening and thus locked, but with thepossibility of opening the door again by exerting a correspondingpulling force. This is not possible with the snap fastening of the base19. In order to disassemble the latter, a tool must be applied orextensive force must be exerted by the fingers to press the two pushelements 22 into the housing against the force of the associated springuntil the edges of the associated opening 12 move away along the steepinclined surface 24.

In the embodiment form according to FIG. 1A, the bevel of the thin wall14 lies directly next to the bevel of the frame 16 and only thethickness of the plate separates them from one another. In theembodiment form according to FIG. 11B, the arrangement is selected insuch a way that this distance is greater, which may sometimes beadvantageous. The base part is turned around for this purpose.

FIGS. 10A, 10B, 10C and 10D show different views of the embodiment formin which the thin wall 14 is detachably fixed to the door frame 16 usingthe twofold snap fastening 19, 20 according to the invention.

When the door leaf has no bevel at which a suitable receiving openingcan be arranged for snapping in, then, in the case of a switch cabinetwith a door frame 116 and a door leaf 114 according to FIGS. 12, 13A and13B, this door leaf 114 is outfitted with webs 17 which proceed from thefree surface of the door leaf, are located opposite one another, andhave openings 21 into which push elements 123 can move.

In FIGS. 15A, 15B, two thin walls are connected to one another by a basepart according to the invention. The two thin walls 14 and 16 are heldby means of self-locking push elements 323 in such a way that they canonly be detached from one another by a tool. The associated housing canbe produced from an injection-molded metal alloy or plastic and has theshape shown in FIG. 15B, while the same shape is produced in FIG. 16Bthrough sheet-metal rolling. A web 61 can be freed according to FIG. 16Aby means of two notches 59 and can subsequently be pressed into theprofile by a pressing tool as is shown in FIG. 16C. The pressed inportion then serves as a projection for limiting the movement of thepush elements 323.

This embodiment form of rolled sheet metal can be expanded to a shapethat is shown in FIGS. 17A, 17B and 17C in which two pairs of pushelements without an intermediate base plate are held so as to bedisplaceable in a profile shape providing sufficient space for thesepush elements. The two pairs of push elements can also be separated fromone another. According to FIG. 18, this is made possible by means of aninverted convolution of the sheet-metal material (see 331). Theembodiment form shown in FIG. 16C can also be injection-molded frommetal or plastic. An example is shown in FIGS. 19A and 19B, and FIG. 20shows the corresponding technique in connection with a dual-channelprofile. Due to the flexibility of the shoulders 342 according to FIG.16C, indicated by 442 in FIGS. 19A and 19B and by 545 in FIG. 20 showingan injection-molded or plastic version, the respective pair of pushelements 323, 423 or 422 can be inserted while the shoulder projectsout, this shoulder being flexible at the moment of insertion; theshoulder then moves into the recess area and springs back. Therefore, aseparate plug part of the type mentioned with reference to theproceeding embodiment forms can be omitted.

The construction shown in FIGS. 21A, 21B and 21C is similar to thatshown in FIGS. 19A, 19B, but two pairs of push plates 622 are providedhere instead of one pair of push plates 422 according to FIG. 19C. Inthis case, the head part 620 is connected to the base part 618 by meansof two screws 40, wherein the screw 20 is screwed into a shoulder 41that projects from the base part 618. A headless screw extending intothe movement path of two push elements 622, respectively, for limitingthe movement path is shown at 44. In the arrangement according to FIGS.22A, 22B, 22C, the push elements 722 have an opening 46 which extendsparallel to the plane of the thin wall and in which the spiral spring728 can be inserted. This spring is supported at the bottom surface 48of a pocket hole 50 receiving the spring, wherein it presses against theedge 52 of the push element 722 with its other end and accordinglypresses this push element 722 against the edge of the opening in thethin wall 714. The holding element 722, which is formed by a flat diskas can be seen in FIG. 22C, is arranged in a correspondingly shapedslot-shaped space 54 that is arranged in the head part 720. Theslot-shaped space 54 extends into the head part 720 (see FIG. 22A) farenough so that the push element 722 can be inserted in its entirety. Theoutward movement is limited when the push element 722 has reached thebottom surface 48 for the spring 728 with its rear edge of the opening46 because this edge 56 then strikes against the end of the spring 728and the spring accordingly loses its pressing action against the metalpiece 722.

FIGS. 24A, 24B, 24C show that the only difference compared to theconstruction according to FIGS. 6A to 6C consists in that there is adistance B between the contact surface 360 and the inclined surface 624that is capable of receiving the thickness of additional thin walls 816,817. Accordingly, the embodiment form according to FIGS. 24A to 24Cdiffers from that according to FIGS. 22A to 22C in that the push element822 is not narrow, but, on the contrary, has a large width, andsemicircular recesses 64 are provided at the side surfaces 62 forreceiving the half or the cross section of the spring 828. The secondhalf of the wire spring 828 is received by a corresponding space whichhas a semicircular cross section, is formed in the head part 28 andcorresponds to the slot part 54 according to FIG. 22A.

FIGS. 25A, 25B, 25C show an embodiment form which makes it possible, onthe one hand, to block the holding elements 922 in their extendedposition shown in FIG. 25A by means of a plug 66 but also, on the otherhand, to pull back the holding elements 922 against the force of thespring 988 after removing the plug 66 by means of a key 68 andaccordingly makes it possible to disengage the connection element fromthe thin wall 914 whenever this is desirable. Another advantage of thisembodiment form consists in the inclined surface 70 (see also thedetailed views of the holding elements 922 in FIGS. 26A, 26B and 27A,27B, 27C) which causes these holding elements to be forced outward indirection of the channel walls 72 by the pressure of the spring 928 sothat friction occurs in the channel and possibly already fixes theholding elements 922 to a sufficient extent that the fixing plug 66shown in FIG. 25A is no longer required. When the plug 66 is not neededfor securing the holding elements 922, the plug 66 also does not need tobe removed when the unlocking key 68 is introduced through the hole 74in the channel cover 76 into the recess area 78 formed by the twoholding elements 922. When the key 68 is turned in the counterclockwisedirection with reference to FIG. 25A, the sides 80 of the key pressagainst the end face 82 of the recess area 78 and the key moves theholding element 922 into the channel until the position shown in FIG.27C is reached, at which time the key is turned by 90° and is held byitself. The entire unit shown in FIG. 25A can then be pulled out of theopening in the thin wall 914, whereupon the structural components partsthat may possibly be clamped together can be separated again.

Also, the receiving space 84 for the springs 928 is clearly shown inFIGS. 26A to 27C.

FIGS. 28A to 28D show a flat metal piece as holding element 102 whichhas an opening 1046 for receiving a spring 1028 and two projections 1066which are located opposite one another and rest against the spring 1028while supporting the latter so as to form a handling unit comprising theholding element and spring similar to the illustration in FIGS. 14A to14D.

This unit can be received in the correspondingly shaped slot space 1054in the head part 1020 (see FIG. 28A), wherein the cutout 1084 providedfor the spring is shorter than the corresponding cutout 1054 for theholding element 1022, so that the spring 1028 is provided with a contactsurface when the holding element 1022 is pushed into the position shownin FIG. 28A.

When a nub 86 is arranged at the end of the cutout 1084 for the spring,the spring can be secured and the holding element 1022 with the spring1028 can be prevented form falling out.

In the embodiment form according to FIGS. 30A, 30B, 31, 32A and 32B, thechannel 1134 opens upward (see FIG. 31) for technical reasons relatingto manufacture. The holding elements 1122 are still guided because theholding element 1122 is constructed so as to be L-shaped in crosssection, so that a T is formed by two L-shaped elements runningalongside one another as can be seen in FIG. 30B. Since the holdingelements 1122 are not locked in this embodiment form, the insertion ofthe connection part 1110 into the opening 1112 of the thin wall 1116 isfacilitated when a straight edge 88 is provided in front of the run-inslope 90. The inclined surfaces formed by the body part 1120 (see FIGS.30B and 31) also facilitate insertion into a rectangular opening 1112 ina thin wall 1116.

A one-piece T-shaped clip element can also be inserted into a pockethole with a T-shaped cross section, e.g., in the front side of theclosure housing, although this clip element would likewise open upward.

The shape of the opening need not be rectangular as in the embodimentforms shown above; it can also be round if the provided rotatability isnot troublesome or if this rotatability is even desired, or two openingsor nubs prevent a rotation or have a cross shape (similar to the “RedCross”) and then have, e.g., four holding elements that are offsetrespectively by 90°, which provides a particularly reliable preventionagainst rotation in addition to an especially good holding strength, oran oval shape or some other suitably appearing shape that would beadapted to the head part.

A practical embodiment example for the embodiment form shown in FIGS.25A, 25B to 27C is shown in FIGS. 34 to 37. In this case, a thin wall1214 is held on a wall support 1216, the wall 1214 and carrier 1216 eachhaving an opening 1212 and 1213, respectively, through which a snapfastening element 1210 can be inserted and locked behind the carrier ascan be seen in FIG. 34A. The snap fastening part 1210 has a hole 1274 atthe front end as well as at the rear side for unlocking so that thecorresponding key 68 can be inserted from the front as well as from theback in order to unlock the fastening element again and separate thethin wall 1214 from the wall support 1216.

This unlocking from the front and from the back is illustrated in FIGS.36 and 37, respectively.

For visual reasons and also to prevent the penetration of dust, the hole1274 can be closed by a plug 66 which could serve at the same time tolock the holding element 1122 so as to prevent unwanted removal.

Another embodiment example is shown in FIGS. 39 to 44. FIG. 38 shows arectangular opening 1313 in a thin wall 1314 and an opening 1312 in awall support 1316. The opening 1413 and opening 1412 have two paralleledges and rounded edges perpendicular to the latter (see FIGS. 38A and38B). All of the openings form notches in the parallel walls locatedopposite one another.

A housing 1335 can be clipped into the opening 1312 of the thin wall1314. The clipping process is realized by means of protuberances 1337which project from the plastic housing but which are flexible to theextent that they can yield when inserting the edge of the bore hole1312. The housing is secured inside the thin wall 1314 in this way. Thehousing 1335 forms channels or guides 1333 for plates or push elementswhich can be pulled back in a manner similar to that shown in FIGS. 25Ato 27C when a knob 43 that projects inward through the flangearrangement 1318 and is supported therein is rotated by a quarter turn,wherein the holding elements 1322 are pulled back until the opening ofthe wall support 1318 is released, wherein the recesses in the opening1312 allow the passage of the protuberances 1337 that are not pulledback. This process is illustrated in FIG. 40D. The construction can becarried out according to the embodiment forms shown above in such a waythat the triggering device locks at 90° so that a plurality of snapfastenings 1310 of the kind mentioned above are kept unlocked at thesame time and can be pulled out of a wall support 1316.

An example is also shown in FIG. 44 in which two snap fastenings 1310 ofthe kind mentioned above are arranged on a thin wall 1314, e.g., a wallelement or a closure arrangement of a wall support 1316, for example, onthe frame of a housing. The flange 1318 of the snap fastening can alsocomprise a grip (see FIGS. 43B and 43A) which may enclose the actuatingscrew 43.

In the embodiment form shown in FIGS. 45A, 45B and 45C, a snap fastening1523 which is not self-locking and a self-locking snap fastening 1522are located in the housing 1535. The self-locking snap fastening 1522secures the arrangement at the wall support 1415 and the snap fastening1523 that is not self-locking can hold a thin wall 1516 at the wallsupport 1415 in a removable manner.

FIG. 46 shows that the two types of snap fastening 1522, 1523 can beoffset relative to one another with respect to the distance from theplane of the thin wall 1540. The snap fastening shown in FIG. 47 belongsto the arrangement shown in FIG. 45B. The opening provided for the snapfastenings that are not self-locking is designated by 1512 and issomewhat larger than the opening which is required for the self-lockingfastening and which is shown somewhat closer at 1513.

Different designs such as those that have already been described indetail above can be used as plate elements.

FIGS. 48A and 48B show a self-locking version. FIG. 48C shows acorresponding version that is not self-locking.

FIGS. 49A, 49B and 49C show an example of plates such as those shown ina similar form in FIGS. 30 to 32.

FIGS. 50A and 50B show two views of a snap fastening with plates whichare not self-locking. The base part can be screwed on in an adjustablemanner as a bracket. This adjustability makes it possible to adapt to ahung door.

In FIG. 51A to FIG. 53, the snap fastening 1710 according to theinvention serves as a connector for two thin walls 1714, 1716, such assheet metal, which are provided at the connection location with openings1712, 1713. The connector serves as a substitute for a weld connectionwhich is very difficult in many metals such as stainless steel and leadsto discoloration or as a substitute for a complicated screw connectionwhose parts, if they fall out, can lead to short circuits in switchcabinets, or for rivets, wherein the snap connection according to theinvention can also be used wherever the connection location is poorlyaccessible, or inaccessible, when the connection is to be produced.

The solution consists in that the base part 1718 and head part 1720 havea shared housing 1735 with holding elements 1722, 1722′ which arearranged in both parts 1718, 1720 in an approximately mirror-invertedmanner with respect to the center line of the housing and which areshaped in such a way that they are self-locking in the insertiondirection against spring force 1728 and engage the edges of the openingby an inclined surface 1724, 1724′, wherein a support edge 1718 whichcovers the contacting edges of the opening 1712 in one wall 1716 andwhich can be received (FIG. 51A to 53) by the opening 1713 in the secondwall 1714 extends along the outer wall of the housing 1735 at the heightof the inclined surface 1724 of the holding elements of the head part1720 substantially parallel to the insertion direction.

To this extent, the arrangement is similar to that in FIG. 2, exceptthat only the base part 22 has self-locking holding elements 22, but thehead part 20 does not. In the arrangement according to FIG. 51A, theslope of the inclined surface 1724 is greater and is accordingly alsoself-locking.

In this case also, the openings need not necessarily be rectangular;other shapes such as a circular shape can also be realized. The housingthen has a correspondingly adapted outer contour.

Instead of using the plug 1766 to limit the path of the holdingelements, a cross-pin which extends through the recesses 1779 and isheld in the longitudinal walls, not shown, can also be provided.

It is also possible, in kinematic reversal, to provide the holdingelements with projections which extend into recesses or elongated holesformed by the housing and limit the movement path of the holdingelements.

Instead of using holding elements that are displaceable linearly, aswiveling movement can also be used in many cases. For example, FIG. 54shows a snap fastening which is characterized in that the holdingelements 1822 are levers that are arranged at a distance (A) from thethin wall 1816 so as to be rotatable around an axis parallel to theplane of the thin wall 1816 (FIG. 54).

Alternatively, the snap fastening can also be characterized in that theholding elements 1922 are levers arranged at a distance from the thinwall 1916 so as to be rotatable around an axis perpendicular to theplane of the thin wall 1916 (FIGS. 55A to 55C).

FIG. 56 shows an exploded view of a snap fastening 2010 similar to thatin FIGS. 40A to 40C, but in which a spring 2037 that is insertable intoa housing slot 67 is provided instead of a fastening cam. The snapfastening 2010 is fastened in the opening 2012 of the wall support 2016by these spring parts 2037 inserted at opposite surfaces of the headpart 2020. This situation is shown in FIGS. 60A to 60C.

The thin wall 2014 with its somewhat larger opening 2013 which allowsthe springs 2037 to pass through freely is subsequently attached and isheld by the push elements 2022 as can be seen in FIGS. 61A to 61C.

FIGS. 57A-F (FIG. 57E is an enlarged view) show different views of thesnap fastening according to FIG. 56 in a closed position in which thepush elements 2022 are moved out. The wings 2029 of the rotary knob 2043contact stop faces 69 of the housing and extend into notches 2078 of thepush elements 2022 in such a way that the push elements 2022 are pulledback when the rotary knob 2043 is turned 90 degrees (until contactingthe second stop surface 71) so that the open position shown in FIG. 58Eis reached.

FIGS. 58A-E shows different views of the snap fastening according toFIG. 56 in this open position. FIG. 59 shows a perspective view of thesnap fastening according to FIG. 56 before it is mounted in a wallsupport and before the thin wall is mounted at the wall support by meansof the snap fastening. FIG. 60A is a perspective view of the snapfastening according to FIG. 56 after it is mounted in a wall support andbefore the thin wall is mounted at the wall support by means of the snapfastening. FIGS. 60B-D show other views of the situation shown in FIG.60A, and FIG. 61A shows a perspective view of the snap fasteningaccording to FIG. 56 after it is mounted in a wall support and after thethin wall is mounted at the wall support by means of the snap fastening.FIGS. 61B-D show other views of the situation shown in FIG. 61A.

The rotary knob 2043 has a flange 73 on which color markings 75, 77,e.g., a red dot and a green dot, are arranged. This flange is rotatablymounted between the housing surface 81 and a cover 83 that can beclipped to the latter. The housing (or its cover 83) has markings in theform of notches 85 which indicate the operating position of the pushelements (open, closed) in that the notch or opening 85 is arranged insuch a way that it allows the colored dot or surface region to be seen(see, e.g., FIG. 60D) in a certain position of the rotary knob relativeto the housing (e.g., in two end positions).

COMMERCIAL APPLICABILITY

The invention is commercially applicable in switch cabinet construction.

While the foregoing description and drawings represent the presentinvention, it will be obvious to those skilled in the art that variouschanges may be made therein without departing from the true spirit andscope of the present invention.

Reference Numbers 10, 110, 210, 310-2010 snap fastening, connection part11 hinge 12, 112, 1112, 1212, 1712, 2012 opening in the wall support 13,113, 1213, 1313, 1713, 2013 opening in the thin wall, female plug-inpart 14, 114, 714, 914, 1314, 1514, thin wall 1714, 2014 15, 115 grip,handle, recessed handle 16, 816, 1116, 1216, 1316, 1716, wall support1816, 2016 17, 817 web, thin wall 18, 118, 218, 318, 418, 618, flange,base part, base plate, 1618, 1718, 2018 bottom plate, fastening plate119, 219, 319 bolt, bore hole, base part 20, 320, 720, 1020, 1720, 2020head part, male plug-in part 21 opening 22, 122, 322, 422, 622, 722,holding elements, push elements, 822, 922, 1022, 1122, 1322, plates1522, 1722, 1722′, 1822, 2022 23, 123, 223, 323, 423, 1523 pushelements, holding elements 24, 424, 1724, 1724′ roof shape, steeper part25, 25′ triangle side, inclined surface 26 roof shape, flat part 27, 27′triangle side, inclined surface 28, 728, 828, 928, 1028, 1728, springelement 2028 29, 2029 tool 30 axis 331 inversion 32 opening 33 guide,channel 34, 1134 guide, channel 35, 935, 1335, 1735 housing 36 edge ofopening 37, 2037 fastening cam, spring part, spring element 38 end face,stop surface 39 end face, stop surface 40 screw 41 shoulder 42, 342,442, 542 shoulder, projection, pin 43, 2043 rotary knob, key 44 headlessscrew 45 grip device 46, 146 opening 47 opening 48 bottom surface 49diameter of the head part; movement direction 50 pocket hole 51projecting end of the push element 52 edge 53 projecting end of theholding element 54, 1054 slot space 56 edge 57 support shoulders 58 arm59 notch 360 stop surface 61 web 62 side surface 64 recess 66, 1766plug, shoulder, projection, pin 67 housing slot 68 key 69 stop surface70 inclined surface 71 stop surface 72 channel wall 73 flange 74, 1274hole 75 color marking 76 channel cover 77 color marking 78 recess area79, 1779 notch, recess 80 sides 81 surface 82 end face 83 cover 84, 1084receiving space 85 notch 86, 186 nub, projection 88 straight edge 90run-in slope A distance B portion

1. A snap fastening fixing a thin wall, such as a housing wall, doorleaf, or shutter, which is provided with an opening, to a wall support,such as a housing frame, door frame, wall opening edge, which islikewise provided with an opening, comprising: a base part that can bearranged at the wall support in its opening; a head part which extendsaway from the base part and which has a diameter that initiallyincreases and then decreases again in its longitudinal section from anend of the head part in direction of the base part; said head part beinga male-plug-in part which, by overcoming a spring force acting radiallyoutward in direction of the diameter, can be received by an undercutfemale plug-in part that is formed or carried by the opening of the thinwall; said head part having a guide or channel to accommodate at leasttwo push elements or holding elements which are pushed by at least onespring into a position in which they project out over the end of theguide or channel; ends of the push elements or holding elementsprojecting from the guide or channel being triangular or ball-shaped ina projection plane extending perpendicular to the thin wall; said basepart being formed with a plate which overlaps the longitudinal edges ofthe opening in the thin wall; and said snap fastening having anadditional base part with an additional head part, said additional basepart and head part having substantially the same construction as theother base part and head part, said base parts lying at opposite sidesof said base plate so as to function as a connector between the thinwall and the wall support, said snap fastening is shaped in such a waythat one set of base part and head part is self-locking in an insertiondirection against the spring force and engages the edges of one of theopenings of one of the thin walls or the wall support by the ends of thepush elements or holding elements so as to cover the contacting edges ofsaid opening and the other set of base part and head part is received onthe other opening of the other of the thin wall or wall support to coverthe contacting edges of said other opening, therefore maintaining theconnection between the thin wall and the support wall.
 2. The snapfastening according to claim 1, wherein the base plate of the head partis formed or carried by the web of the base part.
 3. The snap fasteningaccording to claim 1, wherein the base part has a greater longitudinalextension than the head part and, with its web, forms support shouldersfor the thin wall.
 4. The snap fastening according to claim 1, whereinthe free ends of the holding or push elements of the base part have anasymmetric roof shape such that the base part can be inserted into asuitable opening in a thin wall or wall support by inserting thelongitudinally displaceable holding or push elements while guiding thepart of the roof shape with the flatter inclination, but a backwardmovement while guiding the steeper part of the roof is impossiblebecause the holding or push elements are self-locking in their guide. 5.The snap fastening according to claim 1, wherein a tool such as a keywhich is capable of pulling back the holding and push elements againstthe spring force by turning it can be inserted from the front and/orback into the housing comprising the self-locking snap fastening.
 6. Thesnap fastening according to claim 1, wherein the base part is secured byscrew bolts.
 7. The snap fastening according to claim 1, wherein thebase part is formed with fastening holes.
 8. The snap fasteningaccording to claim 1, wherein the base part is a side of a pressed metalprofile.
 9. The snap fastening according to claim 1, wherein the basepart is a side of a rolled sheet-metal profile.
 10. The snap fasteningaccording to claim 1, wherein the base part is a side of aninjection-molded plastic profile.
 11. A drawer or rack with a frontplate and a receptacle, wherein the front plate is the thin wall and thedrawer receptacle is the wall support according to claim 1, and furthercomprising at least one snap fastening according to claim
 1. 12. Acabinet with a thin wall and a wall support according to claim 1, andprovided with at least one snap fastening according to claim
 1. 13. Acabinet according to claim 12, wherein at least one handle or recessedgrip is arranged in an opening in the thin wall to interact with the atleast one snap fastening.
 14. A cabinet according to claim 13, whereinthe thin wall has webs with openings for receiving the symmetricallyroof-shaped ends of the non-self-locking snap fastening.